Heat operated refrigerator operable on gas or electricity



N 1966 G A GRUBB 3,284,610

HEAT OPERATED REF RIGERATOR OPERABLE ON GAS OR ELECTRICITY Filed Dec.14, 1964 2 Sheets-Sheet l INVENT ATTORNEY 2 Sheets-Sheet I A ATTORNEY G.A. GRUBB HEAT OPERATED REFRIGERATOR OPERABLE ON GAS OR ELECTRICITY Nov.8, 1966 Filed Dec. 14, 1964 United States Patent 3 284 610 HEAT OPERATEDREFRIGERATOR OPERABLE 0N GAS 0R ELECTRICITY Gunnar Axel Grubb, Bromma,Sweden, assignor to Aktiebolaget Electrolnx, Stockholm, Sweden, acorporation of Sweden Filed Dec. 14, 1964, Ser. No. 417,936

Claims priority, application Sweden, Dec. 16, 1963,

13,979/63 4 Claims. (Cl. 219279) My invention relates to heat operatedrefrigerators operable by gas or electricity.

It already has been proposed to control the operation of heat operatedrefrigerators of this kind by a control member movable between twooperating positions, in one of which the refrigerator is adapted to beoperated by gas and in the other by electricity.

In such a control, movement of the control member between its twooperating positions is essentially unrestrained, and the control membermay be freely moved to the position which renders the refrigeratoroperable by the desired source of heat. This is objectionable when oneof the sources of heat is not available for operation of therefrigerator, as, for example, when the refrigerator is installed in atravel trailer located in an area where electricity is not available,because the control member inadvertently or accidentally may be movedfrom the position which renders the refrigerator operable to the otherposition associated with the source of heat that is not available. Undersuch conditions, the refrigerator will not function to preserve food.Further, it is desirable to employ a control which is operable todisconnect the refrigerator not only from one or the other of thesources of heat but also from both sources at the same time to makecertain the refrigerator will not start operating if not desired if thecontrol member inadvertently is left in an operating position.

It is an object of my invention to provide for a heat operatedrefrigerator a control having a control member movable in a range fromeither one of two operating positions to the other of the two operatingpositions to adapt the refrigerator for operation by gas or byelectricity, the control functioning to interrupt and halt movement ofthe control member during its back and forth movement in the range at aposition which is intermediate the two operating positions and effectiveto disconnect the refrigerator from both sources of heat at the sametime.

The invention, together with the above and other objects and advantagesthereof, will be more fully understood upon reference to the followingdescription and the accompanying drawing forming a part of thisspecification, and in which:

FIG. 1 illustrates more or less diagrammatically heat operatedrefrigeration apparatus embodying the invention;

FIG. 2 is a fragmentary sectional view taken at line 22 of FIG. 1;

FIG. 3 is an elevational view taken at line 33 of FIG. 1 to show partsmore clearly; and

FIG. 4 is a sectional view like one taken at line 44 of FIG. 3illustrating a modification of the invention.

In FIG. 1 of the drawing, the invention is shown in connection with heatoperated absorption refrigeration apparatus containing an inert pressureequalizing gas. Refrigerant vapor is expelled from absorption liquid ina vapor lift pipe of a vapor-expulsion unit 11 and passes through theupper part of a standpipe 12 and a conduit 14 to a condenser. Therefrigerant vapor, such as ammonia, is liquefied in the condenser andflows into an evaporator in which the refrigerant evaporates anddiffuses into an inert gas, such as hydrogen, to produce a refrigeratingeffect within the thermally insulated interior of a refrigeratorcabinet. The resulting gas mixture of refrigerant and inert gas flowsfrom the evaporator to an absorber including a coil 15 and an absorbervessel 16 to which the lower end of the coil is connected, such gasmixture entering the absorber vessel 16 through a conduit 17.

In the absorber refrigerant is absorbed from the gas mixture intoabsorption liquid, such as water, which is delivered thereto through aconduit 18, and the absorption liquid enriched in refrigerant passesinto the absorber vessel 16. The inert gas is returned from the absorberto the evaporator in the path of flow including a conduit 19, and theenriched absorption liquid is conducted through a conduit 20 and innerpipe 21 of a liquid heat exchanger 22 to the vapor-expulsion unit 11.

The raised absorption liquid from which refrigerant vapor has beenexpelled flows by gravity from standpipe 12 through the outer pipe 23 ofliquid heat exchanger 22 and conduit 18 into the upper part of absorbercoil 15. In order to simplify the drawing, the condenser, evaporator andconnections therefor have not been shown, such parts being well knownand their illustration not being necessary for an understanding of thisinvention.

Absorption solution enriched in refrigerant flows from the absorbervessel 16 through conduit 20 and inner pipe 21 of liquid heat exchanger22 into the lower end of vapor lift pipe 10 which is in thermal exchangerelation with a heating tube 24 at 25. The heating tube 24 is arrangedto be heated by an electrical heating element 26 disposed within thetube. Vapor generated in the vapor lift pipe 10 by heating effected bythe heating tube 24 raises liquid therein by vapor lift action and fiowsfrom the upper end thereof through the upper part of standpipe 12 intoconduit 14 and passes to the condenser, as previously explained.

The vapor-expulsion unit 11 in its entirety, together with a majorportion of the liquid heat exchanger 22, are embedded in a body ofinsulation 27 retained in a metal shell or casing 28 having an opening29 at the bottom thereof. The heating tube 24 is embedded in a part ofthe insulation 27 which is intermediate the ends thereof and spaced fromthe top and bottom ends of the shell 28. Electrical conductors 30 and 31for the electrical heating element 26 pass through the bottom opening 29of the shell 28 and extend through the insulation 27. The heating tube24 snugly receives the heating element 26 which may comprise a cartridgehousing an electrical wire or the like having a relatively highresistance that generates heat when connected to a source of electricalenergy. It is usually the practice to provide a passage in the body ofinsulation 27 which extends to the exterior of the insulating body, sothat the electrical heating element 26 may be readily inserted into andremoved from the heating tube 24.

As shown in FIG. 1, the vapor-expulsion unit 11 is arranged to beoperated at will by two independent sources of heat, each of which aloneis capable of supplying heat at an adequate rate and at a sufficientlyelevated temperature to the vapor lift pipe to effect normal operationof the refrigeration apparatus under all conditions under which theapparatus is intended to be operated. This is accomplished by providinga second heating flue 32 which is in thermal exchange relation with thevapor lift pipe 10 at 33. A fluid fuel burner 34 is arranged to besupported in an upright position within the bottom part 32a of theheating flue, so that the combustion gases will be used most effectivelyfor heating the heating flue 32. The burner 34 is connected to a sourceof supply of gaseous fuel by sections 35a and 35b of a pipe 35 in whichis connected a valve 36.

As shown in FIG. 2, the valve 36 for controlling the supply of gaseousfuel to the burner 34 includes a casing 37 of cylindrical shape which isfixed to a suitable support (not shown). Within the casing is positioneda rotatable valve member 38 fixed to a shaft 39. The valve member 38 isformed with a passage 40 which connects the pipe 35 and burner 34 whenthe valve member is in the position illustrated in FIG. 2.

' The electrical heating element 26 is connected by conductors 30 and 31to a source S of electrical energy in an electrical circuit which alsoincludes conductors 41 and 42 and an electric switch 43. The switch 43comprises a member 43a of cylindrical shape which is formed ofelectrically conductive material and fixed to the shaft 39 and insulatedtherefrom in any suitable manner. Brushes 44 and 45, to which theconductors 41 and 42 are connected, are adapted to bear against theperiphery of the switch member 43a. The periphery of the switch member43a is provided with an insulating section 46 over which the brushes 44and 45 move when shaft 39 is rotated.

When refrigeration apparatus like that illustrated in FIG. 1 is intendedto be operated electrically, the electrical heating element 26 isconnected to the source S of electrical energyf When the refrigerationapparatus of FlGpl is intended to be operated by gaseous fuel, theburner 35 is connected to the source of supply of the fuel and ignited.Accordingly, the relationship of the valve member 38 and the insulatingsection 46 of the switch 43 is such that in a first position of theshaft 39 the valve 36 is open and the brushes 44 and 45 engage theinsulating section 46 of the switch 43, and in a second position of theshaft 39 the valve 36 is closed and the brushes 44 and 45 are removedfrom the insulating section 46 of the switch 43. The shaft 39 can beturned either to one of two positions, namely, a first valve openposition, or a second switch closed position which will render theelectrical heating element 26 operable to effect heating of therefrigeration apparatus. In accordance with my invention, the outer endof the shaft 39 is formed with an outer tubular section 39a andjournaled in a circular plate or disk 47 supported in any suitablemanner (not shown). To the shaft 39 in a plane perpendicular to its axisis fixed one end of an elongated control member 48. The control member48 includes inner and outer elements 48a and 48b which are in alignmentand axially separated from one another, as indicated at 49.Alternatively, one of the elements 48a and 48b may be formed with ahollow tubular seeone axially movable within the other. The inner end ofthe inner element 48a passes through openings 50 in the hollow tubularsection 39a of the shaft 39 and is held therein by a cross bar 51 fixedto the element 48a.

A helical spring 52, which extends axially of the adjacent ends of theelements 48a and 48b and bridges the gap 49 therebetween, is fixed atits ends at 53 and 54 to the elements 48a and 48b. The outer end of thecontrol member 48 is provided with a hand grip 55 which extends axiallyof the shaft 39. The control member 48, the extreme outer end of whichmay be pointed, as indicated at 480, is movable in front of a plate 56having suitable indicia EL and O and GAS, the indicia EL and GASrepresenting the positions to which the control member 48 is moved torender the refrigerator operable by electricity and gas, respectively,and the indicium representing the off position to which the controlmember 48 is moved to disconnect the refrigerator from gas andelectricity when one or both of these sources of heat are available.

As seen in FIG. 3, the circular plate or disk 47 is formed with aperipheral surface 57 of arcuate form extending between two radiallyextending walls or abutments 58 and 59 which function as stops at the ELand GAS positions of the control member 48. Adjacent to the stops 58 and59 the peripheral surface 57 is recessed to form grooves or valleys 60and 61 which tion so that they may be telescopically connected withgently slope radially outward toward zones 62 and 63 of the peripheralsurface 57 which are of arcuate shape. Directly opposite the indicium Oof the plate 56 the peripheral surface 57 is formed with a valley ordepression 64 disposed between the adjacent ends of the zones 62 and 63.It will be observed that the parts of the peripheral surface 57 of theplate 47 having the greatest radius are those regions of zones 62 and 63adjacent to the depression or valley 64, and that the radial distancefrom the shaft 39 to the bottom of the valley or depression 64 issubstantially greater than the radial distance from the shaft 39 to thebottoms of the valleys 60 and 61.

To the outer element 48b of the control member 48 is fixed a resilientmember 65 which is of semi-circular form and spring-like in character.When movement is imparted to the shaft 39 by moving the control member48, the resilient member 65 freely rides over the peripheral surface 57.When the resilient member 65 moves radially outward from the valleys 60and 61 to the zones 62 and 63, the control elements 48a and 48b areaxially separated against the tension of the helical spring 52. Hence,the helical spring 52 functions to resiliently bias the resilient member65 against the peripheral surface 57, such biasing action being leastwhen the resilient member 65 is in the valleys 60 and 61 and greatestwhen the member 65 is at the regions of the zones 62 and 63 immediatelyadjacent to the valley 64.

It will be seen that the radially extending walls 58 and 59 are apartwhich determines the angular movement of the control member 48 from theposition EL in which electric operation can be effected and the positionGAS in which gas operation of the refrigerator can be effected. In thesetwo operating positions of the control member 48 the resilient member 65of semi-circular form snugly seats in the valleys 60 and 61. When thecontrol member 48 is moved from the EL position to the GAS position orvice versa, it must move through the 0 position in which the valve 36 isclosed and the electric switch 43 is open. Hence, in the 0 position ofthe control member 48 the refrigerator cannot be operated either by gasor electricity. Further, when the control member 48 is moved in eitherdirection toward the 0 position, the biasing action of the spring 52progressively increases to an optimum value at the opposing side wallsof the valley 64. When the resilient member 65 subsequently moves intothe valley 64 the biasing action of the helical spring 52 is still at avalue closely approaching the optimum value and movement of the controlmember 48 at the 0 position is interrupted and halted in the same mannerthat movement of a vehicle is interrupted and halted when its wheelsfall into a deep ditch. It is then necessary to apply force on thecontrol member 48 in such manner that the movement of the resilientmember 65 out of the valley 64 at the 0 position will be promoted.

It will now be understand that accidental or inad vertent movement ofthe control member 48 from one operating 'position to the otheroperating position is prevented by my improved control which I havedescribed above and illustrated, and that the control embodies thefeature of halting and interrupting movement of the control member inits path of movement at a position in which neither gas or electricitycan be supplied to the heat operated refrigerator.

The circular plate 47 comprises structure defining a curved path ofconvex form having an elongated surface 57 which extends between firstand second regions 60 and 61 of the surface and in which all partsthereof including the first and second regions 60 and 61 are in a singleplane perpendicular 'to the surface, as best shown in FIG. 1. The innerend of the arm 48 is anchored at 39a to the rotatable shaft 39 forangular movement about the axis of the shaft. The element 65 is fixed tothe outer end of the arm 48.

It will now be understood that the shaft 39 and arm 48 function asmounting means for the element 65 to effect movement thereof on thesurface 57 between the regions 60 and 61 by force imparted to the arm48. The arm 48 includes an outer part 48b which is movable in thedirection of its length with respect to an inner arm part 48a. The parts48a and 48b of the arm 48 and the spring 52 therebetween function asmeans for holding the element 65 against the surface 57 by force actingon the element 65 through the outer arm part 48b. The spring 52, whichis under tension functions to bias the outer arm part 48b toward theinner arm part 48a.

The surface 57 at each of the regions 60 and 61 has a recess including abottom and opposing sides. The sides of the recesses at 60 and 61, whichare nearer to the ditch 64, are inclined toward the latter and the sidesthereof, which are removed from the ditch 64, serve as abutments 58 and59 which are in the path of movement of the element 65 when the latteris seated in the recesses at the regions 60 and 61, respectively.

The element 65, after being moved from either of the first and secondregions 60 and 61 toward the ditch 64, is movable on a part of thesurface 57 at either side of the ditch and adjacent thereto and alongeither one of the sides of the ditch 64 to the bottom thereof responsive to a first force imparted thereto which is of one magnitude. Eachside of the ditch 64 is inclined at such an angle to the part of theelongated surface 57 which is adjacent thereto and extends therefromthat the element 65 is movable along the surface 57 toward either one ofthe first and second regions 60 and 61 from the bottom of the ditch 64along either one of the sides thereof responsive tov a second forceimparted thereto at the bottom of the ditch which is of higher magnitudethan the first force.

In addition, a separate lock device can be provided which automaticallyfunctions to lock the control member 48 when it reaches its or offposition. As shown in FIG. 4, such a lock device 66 may be provided atthe inner element 48a of the control member 48. The lock device 66comprises a plunger 67 which is axially movable within a hollow sleeve68 fixed to the inner element 48a. A coil spring 69 is disposed withinthe sleeve 68 and retained therein between the plunger 67 and a flange70 on the sleev The plunger 67 is urged toward the plate 47 by thespring 69. When the control member 47 extends vertically upward and atthe position, the plunger 67 moves into an opening 71 in the plate 47and locks the control member 48 in the O or off position. A flexiblechain or pull cord 72 having one end fixed to the plunger 67 and itsopposite end extending outside the sleeve 68 at the flange 70 may bepulled to withdraw the plunger 67 from the opening 71 in the plate 47and permit the control member 48 to be moved from the 0 position toeither operating position at the valleys 60 and 61 in the peripheralsurface 57.

While I have shown and described particular embodiments of theinvention, it Will be apparent that modifications may be made withoutdeparting from the spirit and scope thereof, as set forth in the claims.

I claim:

1. In apparatus of the class described having a refrigerating system ofthe type alternatively employing gas or electricity as power sources andin which cooling is effected by a heat operated refrigeration unitprovided with a heat receiving part, the part being heated by a gasburner heating means disposed adjacent thereto and means for supplyinggas energy to the burner heating means and also being heated byelectrical heating means and means for conducting electrical energy tothe electrical heating means, the combination of control means connectedto the gas energy supply means and to the electrical energy conductingmeans which is operable to connect one or the other of the energy meansrespectively to its associated heating means, said control meanscomprising structure defining a curved path of convex form having anelongated surface which extends between spaced first and second regionsand in which all parts of the surface including the first and secondregions thereof are in a single plane perpendicular to the surface, anelement means for mounting the element for movement on the elongatedsurface between the first and second regions, means for holding theelement against the surface by force acting thereon in a directionperpendicular to the surface, the control means being operable toconnect only one of the energy means to its associated heating meansresponsive to movement of the element to the first region on theelongated surface and being operable to connect only the other of theenergy means to its associated heating means responsive to movement ofthe element to the second region on the elongated surface, the holdingmeans being operable to hold the element against the elongated surfaceat the first and second regions and at all regions of the surfacebetween the first and second regions thereof, the surface between thefirst and second regions having a depression or ditch of concave formincluding a bottom and opposing sides, each of the sides being inclinedtoward a different one of the first and second regions, the element,after being moved from either of the first and second regions toward theditch, being movable on a part of the surface at either side of theditch and adjacent thereto and along either one of the inclined sides ofthe ditch to the bottom thereof responsive to a first force impartedthereto which is of one magnitude, and each side of the ditch beinginclined at such an angle to the part of the elongated surface which isadjacent thereto and extends therefrom that the element is movable alongthe surface toward either one of the first and second regions from thebottom of the ditch along either one of the sides thereof responsive toa second force imparted thereto at the bottom of the ditch which is ofhigher magnitude than the first force.

2. The combination set forth in claim 1 in which the mounting means forthe element includes an arm having inner and outer ends, a rotatablemember having an axis, means for anchoring the inner end of the arm tothe rotatable member for angular movement about the axis, and means forfixing the element to the outer end of the arm.

3. The combination set forth in claim 2 in which the arm includes innerand outer parts, the outer part being movable in the direction of itslength with respect to the inner part, and the means for holding theelement against the surface including the inner and outer parts of thearm and resilient means therebetween which is under tension andfunctions to bias the outer arm part toward the inner arm part.

4. The combination set forth in claim 1 in which the surface at each ofthe first and second regions has a recess including a bottom andopposing sides, each of the sides of the recesses nearer to the ditchbeing inclined toward the latter and each of the sides of the recessesremote from the ditch being in the path of movement of the element andfunctioning to stop movement of the element when the element is seatedin the recess at which movement of the element is stopped.

References Cited by the Examiner UNITED STATES PATENTS 1,069,518 8/1913Barnett 200-15 2,304,302 12/1942 Crupi 219-279 3,080,729 3/1963 Grubb62497 3,093,978 6/1963 Grubb 62236 3,105,363 10/1963 Van Der Scher 62148RICHARD M. WOOD, Primary Examiner. ROBERT A. OLEARY, Examiner. C. L.ALBRITTON, Assistant Examiner.

1. IN APPARATUS OF THE CLASS DESCRIBED HAVING A REFRIGERATING SYSTEM OFTHE TYPE ALTERNATIVELY EMPLOYING GAS OR ELECTRICITY AS POWER SOURCES ANDIN WHICH COOLING IS EFFECTED BY A HEAT OPERATED REFRIGERATION UNITPROVIDED WITH A HEAT RECEIVING PART, THE PART BEING HEATED BY A GASBURNER HEATING MEANS DISPOSED ADJACENT THERETO AND MEANS FOR SUPPLYINGGAS ENERGY TO THE BURNER HEATING MEANS AND ALSO BEING HEATED BYELECTRICAL HEATING MEANS AND MEANS FOR CONDUCTING ELECTRICAL ENERGY TOTHE ELECTRICAL HEATING MEANS, THE COMBINATION OF CONTROL MEANS CONNECTEDTO THE GAS ENERGY SUPPLY MEANS AND TO THE ELECTRICAL ENERGY CONDUCTINGMEANS WHICH IS OPERABLE TO CONNECT ONE OR THE OTHER OF THE ENERGY MEANSRESPECTIVELY TO ITS ASSOCIATED HEATING MEANS, SAID CONTROL MEANSCOMPRISING STRUCTURE DEFINING A CURVED PATH OF CONVEX FORM HAVING ANELONGATED SURFACE WHICH EXTENDS BETWEEN SPACED FIRST AND SECOND REGIONSAND IN WHICH ALL PARTS OF THE SURFACE INCLUDING THE FIRST AND SECONDREGIONS THEREOF ARE IN A SINGLE PLANE PERPENDICULAR TO THE SURFACE, ANELEMENT MEANS FOR MOUNTING THE ELEMENT FOR MOVEMENT ON THE ELONGATEDSURFACE BETWEEN THE FIRST AND SECOND REGIONS, MEANS FOR HOLDING THEELEMENT AGAINST THE SURFACE BY FORCE ACTING THEREON IN A DIRECTIONPERPENDICULAR TO THE SURFACE, THE CONTROL MEANS BEING OPERABLE TOCONNECT ONLY ONE OF THE ENERGY MEANS TO ITS ASSOCIATED HEATING MEANSRESPONSIVE TO MOVEMENT OF THE ELEMENT TO THE FIRST REGION ON THEELONGATED SURFACE AND BEING OPERABLE TO CONNECT ONLY THE OTHER OF THEENERGY MEANS TO ITS ASSOCIATED HEATING MEANS RESPONSIVE TO MOVEMENT OFTHE ELEMENT TO THE SECOND REGION ON THE ELONGATED SURFACE, THE HOLDINGMEANS BEING OPERABLE TO HOLD THE ELEMENT AGAINST THE ELONGATED SURFACEAT THE FIRST AND SECOND REGIONS AND AT ALL REGIONS OF THE SURFACEBETWEEN THE FIRST AND SECOND REGIONS THEREOF, THE SURFACE BETWEEN THEFIRST AND SECOND REGIONS HAVING A DEPRESSION OR DITCH OF CONCAVE FORMINCLUDING A BOTTOM AND OPPOSING SIDES, EACH OF THE SIDES BEING INCLINEDTOWARD A DIFFERENT ONE OF THE FIRST AND SECOND REGIONS, THE ELEMENT,AFTER BEING MOVED FROM EITHER OF THE FIRST AND SECOND REGIONS TOWARD THEDITCH, BEING MOVABLE ON A PART OF THE SURFACE AT EITHER SIDE OF THEDITCH AND ADJACENT THERETO AND ALONG EITHER ONE OF THE INCLINED SIDES OFTHE DITCH TO THE BOTTOM THEREOF RESPONSIVE TO A FIRST FORCE IMPARTEDTHERETO WHICH IS OF ONE MAGNITUDE, AND EACH SIDE OF THE DITCH BEINGINCLINED AT SUCH AN ANGLE TO THE PART OF THE ELONGATED SURFACE WHICH ISADJACENT THERETO AND EXTENDS THEREFROM THAT THE ELEMENT IS MOVABLE ALONGTHE SURFACE TOWARD EITHER ONE OF THE FIRST AND SECOND REGIONS FROM THEBOTTOM OF THE DITCH ALONG EITHER ONE OF THE SIDES THEREOF RESPONSIVE TOA SECOND FORCE IMPARTED THERETO AT THE BOTTOM OF THE DITCH WHICH IS OFHIGHER MAGNITUDE THAN THE FIRST FORCE.